Highly stable individual differences in the emission of separation calls during early development in the domestic cat

Abstract

Study of the development of individuality is often hampered by rapidly changing behavioral repertoires and the need for minimally intrusive tests. We individually tested 33 kittens from eight litters of the domestic cat in an arena for 3 min once a week for the first 3 postnatal weeks, recording the number of separation calls and the duration of locomotor activity. Kittens showed consistent and stable individual differences on both measures across and within trials. Stable individual differences in the emission of separation calls across trials emerged already within the first 10 s of testing, and in locomotor activity within the first 30 s. Furthermore, individual kittens' emission of separation calls, but not their locomotor activity, was highly stable within trials. We conclude that separation calls provide an efficient, minimally intrusive and reliable measure of individual differences in behavior during development in the cat, and possibly in other species emitting such calls.

Evidence for Individual Differences in Behaviour and for Behavioural Syndromes in Adult Shelter Cats

“…Perhaps surprisingly, individual differences in behavioural responses in most of the tests were unrelated to age or sex, suggesting that the behaviours measured here may be useful for evaluating individual differences in adult cats in general. This is supported by previous studies reporting stable individual differences in cats and other mammals in tests similar to those used here, that is, struggle or restraint tests used in cats [26], mice [31], rabbits [32,72,73], North American red squirrels [74,75] and pigs [33,76]; social separation tests used in cats [29,44,45], horses [77] cows [39,78] and dogs [40]; mouse tests used in cats [51,79]; and human approach tests used in cats [21,25,27,56,57,59], dogs [80], pigs and cattle [81,82]. These tests in their various forms are all relevant to the daily life of most cats, and thus provide a promising basis for assessing cat personality across a wide range of populations and conditions, including in shelter cats.…”

“…Separation/confinement tests are used for personality testing in many animals, particularly in social species [ 37 , 38 , 39 , 40 , 41 ]. Despite the fact that cats are considered only facultatively a social species [ 42 , 43 ], in previous studies this type of test has been successfully used for evaluating individual differences in kittens of the domestic cat [ 44 , 45 ] and adult shelter cats [ 29 ]. Moreover, this test represents a common situation in a cat’s daily life around humans, since cats are often confined in a carrier to take to other places outside their home.…”

Temperament in Domestic Cats: A Review of Proximate Mechanisms, Methods of Assessment, Its Effects on Human—Cat Relationships, and One Welfare

“…Individual differences could be identified early in the life of kittens. The frequency of emissions of separation calls by kittens during brief separation experiments was stable from the third day to the third week of life [ 24 , 56 ]. Therefore, they could be used as an early predictor of cats’ temperaments in infancy, as individuals that vocalized more were more anxious in the first weeks of life than those with a lower frequency of vocalizations, considered to be calmer [ 24 , 56 ].…”

“…The frequency of emissions of separation calls by kittens during brief separation experiments was stable from the third day to the third week of life [ 24 , 56 ]. Therefore, they could be used as an early predictor of cats’ temperaments in infancy, as individuals that vocalized more were more anxious in the first weeks of life than those with a lower frequency of vocalizations, considered to be calmer [ 24 , 56 ]. It remains unknown whether interindividual differences in separation calls and motor activity, apparently stable in the early infancy of kittens, could be useful for predicting temperament in adulthood [ 24 , 56 , 57 ].…”

“…Therefore, they could be used as an early predictor of cats’ temperaments in infancy, as individuals that vocalized more were more anxious in the first weeks of life than those with a lower frequency of vocalizations, considered to be calmer [ 24 , 56 ]. It remains unknown whether interindividual differences in separation calls and motor activity, apparently stable in the early infancy of kittens, could be useful for predicting temperament in adulthood [ 24 , 56 , 57 ]. This hypothesis was not tested in these previous studies, and the question remains open for future investigations.…”